So, the benefit of being a complete pushover, and allowing your fluffly labradoodle to sleep on the bed with you, is that it generates a lot of heat.  Which means LOWER HEATING BILLS!

What I want to know is, where does all that energy come from?  Arthur is such a nut during the day, and he  doesn't eat that much.  Where do the calories to create such warmth come from?

Or does this question just reveal that I never did take biology at an advanced level?  (Did take physics though, and I know all about the law of conservation of energy...which seems to apply here.)